Function: syncViewportUniforms()

function syncViewportUniforms(uniforms, renderer): boolean;

Experimental

Make viewport uniforms match what the renderer is actually drawing into. Primitives call this from onBeforeRender, so it runs for every draw with the GL viewport already set.

• uViewport (device px) is always synced: gl_FragCoord is relative to it.
• On the canvas, uResolution / uPixelRatio are derived from it too. Without this, a primitive added to a scene without Primitive.setViewport kept the 1×1 default resolution, so every screen-space quad covered the whole canvas (spike B: seconds of GPU time per frame).
• Render targets (picking, export) keep the logical size given via setViewport, since their pixel ratio is not the renderer's.

Returns true when the CSS resolution or pixel ratio changed.

Parameters

Parameter	Type
uniforms	Pick<ViewportUniforms, "uResolution" | "uPixelRatio"> & object
renderer	ViewportSource

Returns

boolean